While visiting the cathedral, I noticed this stone of rememberance.

My friend talked about Frideswide with such familiarity as though everyone knew who Frideswide was.
I didn’t even know what gender Fideswide was!
Having also encountered St Frideswide church near Osney Island in Oxford, I decided it was high time I did some research. I quickly learned she was a (single!) woman who had run away from home to avoid getting married. From the Cathedral Blog:
Virtually nothing can be said with much certainty about Frideswide, except that her name, which means Peace (frithes) Strong (withe), is a genuine mid-Saxon name.
[…]
[She] is said to have been born in 680 and to have died on 19 October 727, though the earliest written accounts of her life date only from the twelfth century, the first being that of William of Malmesbury in c.1125.Â
https://www.chch.ox.ac.uk/blog/st-frideswide
The Museum of Oxford (https://museumofoxford.org/st-frideswide-patron-saint-of-oxford) recounts that she founded a church in Oxford and on its destruction, a priory was built. The priory was the basis of the college founded by Cardinal Wolsey, adviser to Henry VIII: Christ Church College.
She is also the patron saint of the city and the university, which explains why people who live and work in and around Oxford speak of her with such familiarity, whereas most others have never heard of her!